/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicMesh3.h
NOTE: Both change stamps are unreliable in many contexts, and may someday get removed. Specifically, they get reset onClear(), copied to the destination rather than incremented in copies and moves, and do not track any changes via access to the buffers directly (throughGetVerticesBuffer(), etc).
void SetShapeChangeStampEnabled ( bool bEnabled )